An ostomy in a trachea bypasses an air passageway obstruction and maintains air flow to a patient. During tracheostomy and cricothyreotomy procedures, complications of injury and collapse of the trachea can result in permanent brain damage or death. These complications arise from trauma to surrounding tissue, an oversized opening of the trachea, or puncture of the posterior trachea wall. Furthermore, quick restoration of a patient's air passageway is critical.
Many approaches for forming an ostomy in a trachea require making an incision in the neck using a scalpel. In an elective tracheostomy, this surgical procedure is typically performed while the patient is under general anesthesia. Use of the scalpel potentially causes undue trauma to surrounding tissue and creates an oversized opening in the soft tissue of the neck. To minimize trauma, it is desirable that the incised opening be small and be enlarged with subsequent dilation.
One prior art technique of dilating an ostomy includes the use of a wire guide to facilitate the introduction of dilators into the trachea. As disclosed in U.S. Pat. No. 4,677,978, a needle and an over-the-needle catheter are inserted into the trachea. The needle is removed, and the catheter is replaced with a wire guide. A tapered, elongated, tubular dilator or a series of telescopically positionable, tapered dilators is positioned over the wire guide and introduced into the trachea. A problem with this technique is the sequential manipulation of several devices by the physician, which is time consuming and complicates the procedure. A modification to this technique eliminates the use of the catheter by placing a wire guide through the needle, as disclosed in U.S. Pat. No. 4,889,112. However, maintaining the point of entry to the trachea by holding the needle in the trachea while positioning a guide wire therethrough increases the risk of injuring the posterior trachea wall. If the needle advances too far, the posterior trachea wall will be perforated.
Another prior art technique of dilating an ostomy is the use of a tapered, elongated, tubular dilator or a series of telescopically positionable, tapered dilators with increasingly larger diameters. A problem with these dilators is that each dilator presents a pointed distal end to the posterior trachea wall when introduced into the trachea. The risk of injury to the trachea is compounded by the toughness of the trachea membrane, which resists the introduction of medical devices. Introducing these elongated dilators requires the application of considerable force. A physician must push the dilator into the trachea yet avoid puncturing the posterior trachea wall. Yet another prior art technique of dilating an ostomy includes the use of a device with a handle and nose, which extends laterally from the axis of the handle. The nose has two jaws that spread apart for separating tissue. This type of instrument offers more powerful dilation than is possible with elongated dilators. One device, for example, is introduced into the trachea by positioning the elongated, tapered nose over a wire guide, as in U.S. Pat. No. 4,889,112. A problem with this device is that the unguarded nose must be inserted with precision and manipulated at an angle to prevent perforating the posterior trachea wall. Another device, disclosed in U.S. Pat. No. 4,643,188, has a handle and laterally extending nose with two needle-like jaws. The jaws are tapered and terminate in sharpened, flat, distal blades. A problem with this device is that the jaws present sharpened, distal blades to the posterior trachea wall when introduced into the trachea. As a result, the blades can seriously injure or perforate the posterior trachea wall.